Structure and Dynamics of the LincomycinmCopper(II) Complex in Water Solution by ¹H and [sup13]C NMR Studies.

The copper(II) complex of lincomycin in water solution at pH = 7.15 was characterized by ¹H and [sup13]C NMR and UVmvis spectroscopy. A 1:1 complex is formed in these conditions. The temperature dependence of spinmlattice relaxation rates was measured, showing that all protons behave in a similar fashion and slow exchange conditions prevail. The spinmlattice relaxation rate enhancements were interpreted by the SolomonmBloembergenmMorgan theory. Reorientational dynamics of the complex was approximated by evaluating the motional correlation time of free lincomycin in water solution. The observed proton and carbon relaxation rate enhancements allowed us to calculate coppermproton and coppermcarbon distances that were used for building a molecular model of the complex. The obtained data provide an interpretation of the relatively high stability constant.